The present invention relates to a functional element to be mounted on a retractor for performing cardiothoracic surgery, with a securing device for mounting it releasably on the retractor, and with a device which is used for holding up a beating heart lifted from an operating site and has several spreadable strip-shaped holding fingers.
A functional element of this kind is known from U.S. Pat. No. 6,019,722.
A retractor has a toothed rail, from which a first holding rail is angled off, and a second holding rail which can be driven along the toothed rail via a drive mechanism and which extends parallel to the first holding rail and can be moved toward and away from the latter.
Various functional elements can be mounted releasably on the holding rails.
Retractors of this kind are used, for example, as rib retractors in operations performed on an open and beating heart. The specialist terms thoracic retractor and sternal retractor have also become established for these. When using a sternal retractor, the sternum is divided along its length, and hook-shaped functional elements both on the fixed holding rail and on the movable holding rail are introduced into the surgical opening. By actuating the drive mechanism, the movable and the fixed holding rails are moved away from one another and, in the process, the thoracic cage is spread and an access opening is created through which the operating surgeon can perform surgical procedures in particular on the beating heart.
Further functional elements can be mounted releasably on the holding rails in order to assist the operating surgeon during the operation.
An example of these further functional elements is a Leyla retractor, which is used as an auxiliary instrument for suturing blood vessels. Other functional elements are MIDCAB (minimal invasive direct coronary artery bypass) retractors or IMA retractors for access to the internal thoracic artery, which are used to lift that half of the thorax in which the heart is located in relation to the other half of the thorax, so as obtain further improved access to the heart.
A device which is used for holding up a beating heart lifted from an operating site and which has several spreadable strip-shaped holding fingers is known from U.S. Pat. No. 6,019,722. With this device, a beating heart can be lifted out from the opened thoracic space via its apex and can be held in this position, by which means it is possible to access the posterior wall of the heart in order to operate there. Since the heart is still beating, the problem which arises is that of holding a pulsating organ in a lifted position for the duration of an operation.
The holding device in U.S. Pat. No. 6,019,722 has two types of holding elements. A first type, referred to in said document as a rigid cross support, is made of a rigid non-bendable material. In a first embodiment, this first type is designed as a kind of cup in which the apex of the heart can be placed. The main weight of the heart is carried by the cup. In addition, the heart is sucked into the cup by means of a vacuum. In a further embodiment, this first type consists of two spreadable strip-shaped stiff holding fingers which are applied in the area of the apex of the heart and extend approximately about the circumference of the apex. The apex of the heart is clamped between the stiff holding fingers, and here too suction openings are provided for suctioning the heart.
Moreover, a second type of holding element must be provided, namely respectively at least four further elastically rod-shaped elements extending substantially in the longitudinal direction of the heart. These four holding elements of the second type are bendable and, at their outer ends, they each have a suction cup. By applying a vacuum, and by virtue of their pliability, these four holding elements of the second type can follow the pulsating contraction movements of the beating heart. They are thus able to move substantially in radial directions, viewed in relation to the longitudinal axis of the heart, and for this purpose are movable. In said document, this second type is referred to as a fine support means. In the embodiment with the spreadable strip-shaped holding fingers, there are therefore six holding elements in total, two of the first type and four of the second type, which ensure that the beating heart is held up. The basic principle of this heart holder is to support the main weight of the heart in the area of its apex via the rigid cross support (gross weight support means) and additionally to immobilize it by vacuum. The elastic fine support means are used for lateral support and follow the contraction movements of the heart.
Because so many holding elements, namely six, are present, it is necessary to have a large number of bearing points and holding points on the outer surface of the heart, but this necessarily restricts or obstructs the access to the heart. The purpose of lifting the heart is after all to gain access the outside of the beating heart, in particular to the posterior wall of the heart, and perform surgery there. The cage consisting of a total of six holding fingers considerably impedes this access, however.
Moreover, the construction is extremely complex and necessitates production and handling of two completely different types of holding elements.
It is therefore an object of the present invention to make available a functional element of this type which is of much simpler design, is easier to handle and causes less obstruction of the held heart, but which still guarantees that the heart is held up securely.